Reduced β-lactoglobulin IgE binding upon in vitro digestion as a result of the interaction of the protein with casein glycomacropeptide

The aim of this work was to evaluate the effect of the presence of casein glycomacropeptide (CMP) on the in vitro digestibility and potential allergenicity of β-lactoglobulin (β-lg)-CMP mixtures. The digestion products were analyzed by RP-HPLC and RP-HPLC-ESI-MS/MS. The potential allergenicity of the digestion products was studied by human IgE binding by inhibition ELISA with serum samples from children with clinical allergic symptoms to β-lg. No differences were observed by HPLC in the mixtures hydrolysates due to CMP-β-lg interactions. RP-HPLC-ESI-MS/MS results showed different peptides occurring in the mixtures hydrolysates. Additionally, it was observed a significant reduction of β-lg IgE binding in the presence of CMP. The disappearance of epitopes in the digested mixtures could explain the lower IgE binding observed in these systems compared to β-lg. It can be concluded that the presence of CMP in products containing β-lg may modify the digestion products that may reduce the potential allergenicity of β-lg.